Fermentative production of piperazinium dilactate

In order to test whether piperazinium dilactate can be produced by fermenta tion in its exact stoichiometric composition without losses of yield, the k inetics of cell growth and lactate production were investigated in the batc h cultivation of Lactobacillus paracasei, using piperazine as a neutralizer in pH control. It was found that piperazine dilactate is formed in its sto ichiometric composition at about pH 5.0, and lactic acid fermentation occur red with yields of about 90% under these conditions. Piperazine at concentr ations less than or equal to 50,oil did not affect growth and product forma tion. The presence or absence of piperazine did not produce any significant differences in either the maximum specific growth rate or the maximum spec ific lactate formation rate when piperazine was present or absent (0.65 h(- 1) compared to 0.68 h(-1) and 3.86 g/g x h compared to 3.63 g/g x h, respec tively). The LUEDEKING-PIURET relationship between the two quantities was a lso not changed significantly when piperazine was added. To estimate the op timum parameters for cell growth and lactate formation in the presence of p iperazine, a factorial experiment was designed and carried out under consid eration of the parameter ranges 5.0 less than or equal to pH less than or e qual to 7.0 and 30 degreesC less than or equal to T less than or equal to 3 6 degreesC. In this way, three-dimensional models of the specific growth ra te, the specific lactate formation rate and the lactate yield were obtained .